"I've always said I wanted to end my career on the bench," the longtime prosecutor said Wednesday after learning he had been appointed to soon-to-be vacant seat on the 2nd District Appellate Court.

Birkett will take over for retiring Appellate Court Judge Jack O'Malley on Dec. 13. Birkett had said he wasn't going to seek re-election to his current post in 2012 and was openly lobbying for a judicial post in recent months. Birkett has been the county's state's attorney since 1996.

"I've invested most of my life here, and I love this place," the 55-year-old Chicago native said. "I've made so many friends. I'm going to miss many things about not coming here everyday; the daily interaction with judges, the lawyers and serving the public by helping victims and helping families."

Birkett's successor will be chosen by DuPage County Board Chairman-elect Dan Cronin once he is sworn into office in early December. Cronin, currently a state senator, could not be reached for comment. However, his campaign staff said he was aware of Birkett's appointment and the possibility of needing to find a replacement for the state's attorney.

"Sen. Cronin will carefully review all the statutory obligations related to appointing a new state's attorney," said Cronin spokeswoman Julie Kelly. "He will confer with other board members and elected officials to ensure the process is open and meets all the necessary requirements. Sen. Cronin will consider any qualified candidate who is dedicated to keeping our streets and neighborhoods safe from crime."

Joe Ruggiero, one of Birkett's top lieutenants who heads the office's special prosecutions division, is the rumored front-runner to be Cronin's appointment. Ruggiero and Cronin worked together years ago when they were both assistant state's attorneys. Birkett said Cronin had talked to him about Ruggiero assuming the position if Birkett left. Birkett also said they talked about other prosecutors currently on Birkett's staff. Birkett said he won't influence Cronin's decision.

"The one person that's been mentioned many times is Joe Ruggiero," Birkett said. "If that's his selection, it will be an excellent selection just as any number of prosecutors in this office would be."

Ruggiero said he's had discussions about the appointment.

"I have let Sen. Cronin know I would be very interested in the position and a number of county board members as well," he said.

Ruggiero wouldn't speculate about the possibility of running for the office in 2012 if he weren't appointed.

"I'm not going to get into all that stuff," he said.

Birkett said Illinois Supreme Court Justice Bob Thomas approached him about applying for the appellate appointment after O'Malley announced he was stepping down. Birkett said he sent in the application with a "resume, writing samples, outlines, peer-reviewed bar journal articles and presentations I've made over the years." He had no idea how many others had applied and he was never interviewed by the justices before the seven-member group announced the decision Wednesday.

Birkett submitted the application several weeks ago and never heard anything from the Supreme Court or Thomas in the interim.

"It was nerve racking," he said of the wait. "I really thought about sending them more details and then I would talk myself out of it because I didn't think they'd want to hear from me."

Birkett was the Republican nominee for attorney general in 2002 and was the GOP's lieutenant governor nominee on a ticket with Judy Baar Topinka in 2006. Both campaigns ended unsuccessfully. Birkett ran for re-election as state's attorney in 2008 unopposed. He said at the time he was seeking another term to try convicted killer Brian Dugan for the 1983 murder of Jeanine Nicarico.

The controversial case had sullied the reputation of the state's attorney's office after two people were convicted and sentenced to death only to be later found innocent because of misconduct by prosecutors and sheriff's office investigators. Birkett was not involved in those prosecutions. Dugan had once been a suspect, but then ruled out. He later admitted to the killing after being convicted of other murders. Dugan eventually pleaded guilty to Jeanine's murder and a jury sentenced him to death last year.

"I was not going to leave that case to my successor," Birkett said. "That file was a monster and I was the legal lead. I knew that case and wanted to try it and see it through."

Birkett said he informed his staff earlier Wednesday that he had been appointed to the bench.

"We have done so much together," he told them. "We've protected the taxpayers and ensured honest government. We've held offenders accountable and improved the quality of life for crime victims and their families. You gave me a great resume to submit with my application. Each one of you has played a role in helping me achieve a lifelong goal."